Tap-screw for plugging leaks.



E. A. GEHRKE.

TAP SCREW FOR PLUGGING LBAKS.

APPLICATION FILED APR. 14, 1909. '95 1 5437, Patented Mar. 8, 1910.

EDWARD A. GEHRKE, 0F LINCOLN, NEBRASKA.

TAP-SCREW FOR PLUGGING LEAKS.

fipeciticatlisn of Letters Patent.

Patented Mar. 8, 1910..

Application filed April 14, 1909. Serial No. 489,828.

To all whom it may concern:

Be it known that I, EDWARD A. German, a citizen of the United States, residing at Lincoln, in the county of Lancaster and State of Nebraska, have invented a new and useful Tap-Screw for Plugging Leaks, of which the following is a specification.

The invention relates to improvements in tap screws for plugging leaks.

The object of the present invention is to improve the construction of tap screws for plugging leaks, and to provide simple and easily operated means for effectively stopping the leaks of boilers, pipes, etc., and equipped with means for holding and pre venting a fiber gasket from breaking when pressure is applied.

The invention also has for its object to provide a tap screw plug of this character, adapted to prevent injury to a boiler should it be screwed too tightly into the same.

With ,these and other objects in View, the

invention consists in the construction and novel combination of parts hereinafter fully described, illustrated in the accompanying drawing, and pointed out in the claim hereto appended; it being understood that various changes in the form, proportion, size and minor details of construction, within the scope of the claim, may be resorted to without departin from the spirit or sacrificing any of t e advantages of the invention.

In the drawing Figure 1 is a sectional perspective view of a portion of a boiler, illustrating the manner of repairing leaks withvtap screw plugs, constructed in accordance with this invention. Fig. 2 is a longitudinal sectional View of the tap screw plug. Fig. 3 is a perspective view of the same.

Like numerals of reference designate corresponding parts in all the figures of the drawing.

1 designates a tap screw plug, consisting of a tapered threaded shank or stem 2, having a smooth tapered point and provided with longitudinal tap grooves 3. The tap screw is adapted to cut and thread its way into the leaking portion of a-boiler, pipe,

orthe like in a manner similar to an ordinary machinists tap. The grooves terminate short of the upper end of the threaded stem, which is provided with a smooth uninterrupted threaded the boiler or is applied. v I

The tap screw plug is provided with a round head .5, reduced at the outer end to provide a polygonal wrench-receiving por tion 6, and provided at its inner engaging face with an annular recess 7 for the reception of a fiber gasket 8. The annular recess forms an outer annular wall or flange 9, arranged at the periphery of the gasket and adapted to hold the same in place and prevent the gasket from breaking or crowding out from under the head when pressure is applied thereto. The fiber gasket projects beyond the lower edge of the outer-wall or flange in order to make a water tight joint, as the gasket must be drawn down very tight against the boiler for this purpose. The outer wall or flange not only prevents the gasket from being broken, and forced outward from under the head, but it also limits the inward movement of the tap screw to prevent the same from cracking a boiler.

portion 4, to finally engage pipe to which the screw plug The head of the screw presents a flat engaging face to the gasket, and the screw or' stem is provided at the gasket with a smooth cylindrical portion 10, the threads terminating at the engaging face of the gasket and short of the lower edge of the outer wall of the recess, as clearly shown in Figs. 2 and 3 leaving that portion of the stem smooth so as toavold cutting the inner edge of the gasket and weakening the latter. By this construction the device is prevented from cracking or injuring a boiler should it be screwed too tightly or too far into the same.

The tap screw plug is designed to be constructed in various sizes to adapt it to different kinds of boilers and pipes, and the head .of the screw and the.

gasket will vary with the size of the device.

l-Iaving thus fully described my invention, what I claim as 'newand desire to se cure by Letters Patent, is

In combination with a gasket, a tap screw plug consisting of a tapered threaded stem having tap grooves, and a head provided with an annular recess receiving the gasket and forming an outer wall or flange adapted to hold the gasket in place and prevent the same from breaking and spreading when pressureis applied, said gasket projectinglog . a Water-tight joint, and the said outer wall or flange operating as a stop to limit the insmooth, which fits Within the opening of the 10 gasket.

In testimony, thatI claim. the foregoing as my own, I have hereto aflixed my signature in the presence of two Witnesses.

EDWARD A. GEHRKE.

downwara beyond the lower edge of the Wall or flange, so that the gasket may be drawn down tightly against a boiler to form ward movement of the tap screw to prevent the same from cracking the boiler, and the threads of the stem terminating at the gasket leaving that portion of the steml Witnesses:

W. C. FRAMPTON, JOHN J. LEDWITH. 

